Sulfonic acids, C14-18-alkane hydroxy and C12-20-alkapolyene and C14-18-alkene and C12-20-alkene hydroxy, sodium salts

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25 September 2017 - 14 December 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Remarks:

HPLC-MS/MS

Details on sampling:

- Concentrations: 1.0, 3.2, 10, 32 and 100 mg/L in main test
- Sampling method: Samples were taken at 27 hours and the cell densities determined using a Coulter® Multisizer Particle Counter. At 49 and 72 hours, cell densities were determined using a haemocytometer and light microscope due to the presence of a precipitate in the 32 and 100 mg/L test preparations.
- Sample storage conditions before analysis: frozen

Vehicle:

yes

Remarks:

culture medium

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: test item dissolved in culture medium
- Controls: 6 flasks used for control without algae

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchneriella subcapitata
- Strain: CCAP 278/4.
- Source: Culture Collection of Algae and Protozoa (CCAP), SAMS Research Services Ltd, Scottish Marine Institute

- Culturing media and conditions: same as test

Test type:

not specified

Water media type:

other: reverse osmosis purified deionized water

Limit test:

no

Total exposure duration:

72 h

Remarks on exposure duration:

not specified

Post exposure observation period:

not specified

Hardness:

not specified

Test temperature:

24 ±1 ºC

pH:

pH 7.9 at 0 hours to pH 8.1 at 72 hours

Dissolved oxygen:

not specified

Salinity:

not specified

Conductivity:

not specified

Nominal and measured concentrations:

nominal: 0.1, 1, 10, 100mg/L
measured: 91% to 142% of nominal thereby indicating that the decline in measured concentrations observed was due to adsorption of the test item to the algal cells present rather than instability of the test item under the conditions of the test. As such the results have been calculated based on nominal test concentrations only as it was considered that the algae would have been exposed to nominal concentrations throughout the duration of the test.

Details on test conditions:

TEST SYSTEM
- Test vessel: 250mL conical flask
- Type (delete if not applicable): closed with polyurethane foam bungs to reduce evaporation
- Type of flow-through (e.g. peristaltic or proportional diluter):
- Initial cells density: 5.00 x 10e3 cells/mL
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reverse osmosis purified deionized water
- Culture medium different from test medium: no
- Intervals of water quality measurement: initiation and 72hours

OTHER TEST CONDITIONS
- Sterile test conditions: no
- Photoperiod: continuous
- Light intensity and quality: 7000 lux, warm white lighting (380 to 730 nm)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : 27, 49, 72 hours
- Determination of cell concentrations: coulter counter,
At 49 and 72 hours, cell densities were determined using a haemocytometer and light microscope due to the presence of a precipitate in the 32 and 100 mg/L test preparations

TEST CONCENTRATIONS
- Range finding study: 0.10, 1.0, 10 and 100 mg/L
- Test concentrations: 1.0, 3.2, 10, 32 and 100 mg/L.
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

ca. 89 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

ca. 6.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

cell number

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

ca. 1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

ca. 1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

cell number

Key result

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

ca. 3.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

ca. 3.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

cell number

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): none
- Unusual cell shape: some enlarged cells were observed

- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: At 49 and 72 hours, cell densities were determined using a haemocytometer and light microscope due to the presence of a precipitate in the 32 and 100 mg/L test preparations

Results with reference substance (positive control):

- Results with reference substance valid? yes
- EC50: 1.6 mg/L at 72 hour
- Other:
No Observed Effect Concentration based on growth rate: 0.25 mg/L
No Observed Effect Concentration based on yield: 0.25 mg/L
Lowest Observed Effect Concentration based on growth rate: 0.50 mg/L
Lowest Observed Effect Concentration based on yield: 0.50 mg/L

Reported statistics and error estimates:

not specified

Validity criteria fulfilled:

yes

Conclusions:

Growth Rate: EC50 = 89mg/L, NOEC =1.0mg/L, LOEC =3.2mg/L
Yield: EC50 = 6.9mg/L, NOEC = 1mg/L, LOEC = 3.2mg/L

Description of key information

72 hours:

Growth Rate: EC50 = 89mg/L, NOEC =1.0mg/L, LOEC =3.2mg/L

Yield: EC50 = 6.9mg/L, NOEC = 1mg/L, LOEC = 3.2mg/L

Key value for chemical safety assessment

EC50 for freshwater algae:

89 mg/L

EC10 or NOEC for freshwater algae:

1 mg/L

Additional information

An algal growth inhibition study was conducted (Envigo Research Limited, 2018) to determine the effect of Sulfonic acids, C14-18-alkane hydroxy and C12-20-alkapolyene and C14-18-alkene and C12-20-alkene hydroxy, sodium salts on the growth of green alga (Pseudokirchneriella subcapitata). The study was conducted according to OECD test guideline 201 and EC method C3, and in compliance with GLP.

Triplicate algal cultures were exposed to Sulfonic acids, C14-18-alkane hydroxy and C12-20-alkapolyene and C14-18-alkene and C12-20-alkene hydroxy, sodium salts at concentrations 1.0, 3.2, 10.0, 32.0 and 100 mg/L and incubated under continuous illumination for 72 hours. Six replicate control cultures were also incubated concurrently with the test samples.

The yield of Biomass was affected by treatment with Sulfonic acids, C14-18-alkane hydroxy and C12-20-alkapolyene and C14-18-alkene and C12-20-alkene hydroxy, sodium salts at all levels, and so the No Observed Effect level in terms of Biomass was less than 1.0 mg/L, the lowest concentration tested. An effect on growth rate was also seen at all levels. The NOEC in terms of growth rate was concluded to be 1.0 mg/L. The EC50 in terms of both growth rate and yield were 89.0 and 6.9 mg/L, respectively.